From http://overloaded.io/timing-http-requests-curl

timeing_http_request_curl.sh

$ curl -s -w "%{time_total}\n" -o /dev/null http://www.google.com/
0.095
$ for i in {1..3};do curl -s -w "%{time_total}\n" -o /dev/null http://www.google.com/; done
1.079
0.124
0.106
$ curl -w "@curl-format" -o /dev/null -s http://www.google.com/
time_namelookup:  0.416
               time_connect:  0.435
            time_appconnect:  0.000
           time_pretransfer:  0.435
              time_redirect:  0.000
         time_starttransfer:  0.488
                            ----------
                 time_total:  0.491